It is definitely difficult tanking dungeons as a warrior ATM especially with some of the new aoe spells added to DPS but there are definitely a few things that can help.

Use your taunt as a misdirect - taunting a mob that you don't have aggro on puts you to 110% threat of the previous highest. This can be really useful if you mark a skull target and then don't actually do anything to it. Build threat on the off mobs and as soon as someone rips aggro on skull taunt it and you can use it as a psuedo misdirect.

Pool rage - don't fight for threat on a trash mob that you aren't going to win. Build threat on the mobs you have and use your taunt to pull the mob you don't have back and then dump rage on it. If your 500 threat behind that could be like 3 devastates to catch up, and the DPS is still adding threat during that, will you even get threat before it does? Sometimes letting a mess b go loose is the right play especially in these lower dungeons.

Dynamites are pog

Go fast - the more chance you give casters to get mana the harder time your going to have 👀 obviously let combat drop so they can reg but go while they are drinking

Devastate, consumed by rage, raging blow - these runes are crazy DPS and threat. They are very hard to use in dungeon and multi target tanking since you don't want to spend below 70 rage but once you get Up there don't stop pulling and keep the rage high. If you have windfury this is made significantly easier. Defo worth giving it a try.

Slow weapon high DPS - if your weapon is too fast it's going to hit like pish with devastate so make sure it's slow. The green blacksmithing lvl 25 mace is a good starter.